Catching dead satellites with nets

March 23, 2015, European Space Agency
One capture concept being explored through ESA's e.Deorbit system study for Active Debris Removal - capturing the satellite in a net attached to either a flexible tether (as seen here) or a rigid connection. Credit: ESA

One of humanity's oldest technologies, the humble fishing net, may yet find a new role in space: bringing down dead satellites.

The behaviour of nets in orbit was recently checked on an flying parabolic arcs to create brief periods of weightlessness.

"We shot nets out of a compressed air ejector at a scale-model satellite," explains ESA engineer Kjetil Wormnes.

"We fired 20 nets at various speeds during 21 parabolas over two days. Packed inside paper cartons, the nets were weighted at each corner, helping them to entangle the model satellite.

"The good news is they worked extremely well – so much so that the nets usually had to be cut away with a knife before we could shoot again."

The Falcon 20 aircraft is flown so that for 20 seconds at a time it falls through the sky, effectively cancelling out gravity inside the aircraft.

"Everything was recorded on four high-speed HD cameras," Kjetil added. "The aim is to check the simulation tool we have developed, so that we can use it to design the full-size nets for a debris removal mission."

The rainbow-hued were designed to be easily followed on camera. Of the two variants used, the thinner spun versions proved more effective than the thicker, woven design.

ESA's e.Deorbit mission in 2021 will test the feasibility of removing a large item of debris – either a large derelict satellite or rocket upper stage – to help control the debris levels in busy orbits.

Weightless net testing for derelict satellite capture. Credit: ESA

The best method of snagging an uncontrolled, tumbling satellite is still being decided. ESA's Clean Space initiative to reduce the impact of the space industry on the terrestrial and orbital environments is overseeing studies that also include a robotic arm, a harpoon and an ion beam.

The oldest known was uncovered by a Finnish farmer in 1913. Its willow mesh was carbon dated to 8300 BC, making it several thousand years older than the wheel.

"The main advantage of the net option, whether for e.Deorbit or other debris removal missions in future, is that it can handle a wide range of target shapes and rotation rates," Kjetil explains.

Catching dead satellites with nets
Canada's Falcon 20 parabolic aircraft. Credit: ESA
Weightless net testing. Credit: ESA

Explore further: Image: Polish human centrifuge

Related Stories

Image: Polish human centrifuge

February 19, 2015

How do you prepare for the unique experience of weightlessness on a parabolic aircraft flight? An ESA-led team took a ride on this human centrifuge at Poland's Military Institute of Aviation Medicine.

ESA experts assess risk from exploded satellite

March 5, 2015

After studying the recent explosive break-up of a US satellite, ESA space debris experts have concluded this event does not increase the collision risk to nearby ESA missions in any meaningful way.

Harpooning space debris

June 25, 2014

(Phys.org) —Faced with the challenge of capturing tumbling satellites to clear key orbits, ESA is considering turning to an ancient terrestrial technology: the harpoon.

Capturing derelict satellites adrift in orbit

February 24, 2014

Standard space dockings are difficult enough, but a future ESA mission plans to capture derelict satellites adrift in orbit. Part of an effort to control space debris, the shopping list of new technologies this ambitious ...

Space debris expert warns about dangers of orbital junk

January 12, 2015

The emerging problem of floating space junk becomes more and more evident and bothersome. Spacecraft and satellites are currently subject to high-speed impacts by more than 19,000 trackable objects, mainly old satellites, ...

Recommended for you

When more women make decisions, the environment wins

March 21, 2019

When more women are involved in group decisions about land management, the group conserves more—particularly when offered financial incentives to do so, according to a new University of Colorado Boulder study published ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

LariAnn
not rated yet Mar 23, 2015
It's a shame that provisions for deorbiting decommissioned satellites were not made when satellite launching became widespread. Had it been, we might not be having to deal with so much space junk. It is similar to the styrofoam issue in packaging - the stuff works well but no provision was made for what to do with it once the product it protected is removed for use. Landfills are a ridiculous and wasteful option - it should have been required to be returned to the store or factory for recycling.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.